title: Cancer risk in patients with cholelithiasis and after cholecystectomy: a nationwide cohort study.
abstract: BACKGROUND
  This study examined the association of cholelithiasis post-cholecystectomy with subsequent cancers and evaluated the risk of cancer in patients with both cholelithiasis and cholecystectomy.
  
  
  METHODS
  The Taiwanese National Health Insurance Research Database was used to identify 15545 newly diagnosed cholelithiasis patients from 2000 to 2010, and 62180 frequency-matched non-cholelithiasis patients. A total of 5850 (37.6 %) with cholelithiasis patients received a cholecystectomy. The risk of developing cancer after cholecystectomy was measured using the Cox proportional-hazards model.
  
  
  RESULTS
  The incidence of developing cancer in the cholelithiasis cohort was 1.52-fold higher than that in the comparison cohort (p < 0.001). Compared with patients aged 20-34 years, patients in older age groups had a higher risk of developing cancer. The hazard ratio (HR) for developing gallbladder, extrahepatic bile duct, pancreatic, liver, stomach, and colorectal cancer was 59.3, 10.7, 3.12, 1.90, 1.71, and 1.36-fold higher for patients with cholelithiasis, respectively. After a cholecystectomy, the HR for developing stomach and colorectal cancer was 1.81-fold and 1.56-fold, respectively. The incidence rate ratio was higher for the first 5 years and over 5 years (5.05 and 4.46, respectively) (95 % confidence interval 4.73-5.39 and 4.11-4.84, respectively) in proximal colon and stomach cancer patients with cholecystectomies.
  
  
  CONCLUSIONS
  Cholelithiasis patients have a higher risk of gastrointestinal cancer, particularly of gallbladder and extrahepatic bile duct cancer. Post-cholecystectomy patients have a risk of colorectal and stomach cancer within the first 5 years and persisting after 5 years, respectively. This paper proposes strategies for preventing gastrointestinal cancer.
authors.affiliation: Department of Nuclear Medicine and PET Center, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.
authors.forename: Yen-Kung
authors.initials: YK
authors.lastname: Chen
authors.forename: Jiann-Horng
authors.initials: JH
authors.lastname: Yeh
authors.forename: Cheng-Li
authors.initials: CL
authors.lastname: Lin
authors.forename: Chiao-Ling
authors.initials: CL
authors.lastname: Peng
authors.forename: Fung-Chang
authors.initials: FC
authors.lastname: Sung
authors.forename: Ing-Ming
authors.initials: IM
authors.lastname: Hwang
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002763:Cholecystectomy / Q000379:methods*; D002769:Cholelithiasis / Q000601:surgery*; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors; D055815:Young Adult